Assessment of Soil Carbon in Forests, Plantations and Wastelands Dr. M.N.Jha Forest Research Institute Dehra Dun Workshop on “ Forestry and Climate Change - Assessing Mitigation Potential and Costs”, Sept. 23 –24; 2002, India International Centre, New Delhi

SOC is the largest, ca 15X10 14 kg C reservoir at the earth surface. This reservoir responds positively to, Increased photosynthesis. Increased moisture. Directly to increased atmospheric CO 2 by decreasing the SOC decompositions rates. Increased temperature.

We have ignored SOC because we think it is dead biomass and is directly dependent on the amount of live biomass. It neglects following considerations : A. Increased oxidation of SOC to CO 2 by : - Cultivation of new lands (reduces SOC by1/3and converts it to CO 2 ) - Increased temperature which accelerates SOC decay rates. - Conversion of forests to other land uses. - Decreased rainfall will convert SOC to CO 2 by raising temperature and aerobiosis.

Conversely, soil can remove CO 2 from atmosphere by: B. Accumulating SOC beyond receiving increased NPP, via - Increased rainfall which lowers soil temperature and decreases O 2 diffusion rates thereby reducing oxidation rates. - Minimum-or no-tillage agriculture which should increase SOC. - Increasing atmosphere CO 2 can repress SOC degradation rates.

How might soil be affected by climate changes. Changing temperature Altered rate of microbial activity in soil Will cause break down of organic matter at faster rates Will result in greater release of CO 2

Carbon Stored in : Atmosphere1 unit Soil2 units Therefore, change in temperature and increased microbial activity can lead to significant increase of CO 2 in atmosphere

Soil organic carbon in plantations and natural forests Plantation:Soil Organic C (up to 30 cm depth) (age 16 years)(t/ha) Teak68.0 Chir pine57.2 Eucalyptus99.6 Khair79.6 Shisham98.4 Natural Forests: Deodar392.0 Chirpine338.8 Spruce Kail272.8 Quercus360.0

Organic carbon store in some Indian Soils (up to 30 cm depth) Area SOC store Total SOC Store (m ha) (t/ha) (Gt) Red soil Laterite Alluvial Brown Forest Saline/alkali Black

Soil organic carbon store under different land uses in India Land use Area Organic CStore (up 30 cm depth) (m ha) (t/ ha ) Total Store (G t) Forests Agriculture Pastures Barren land

GHG mitigation potential of different land uses with barren land as base. Land useSOC store Mitigation potential (up to 30 cm depth) 1. Barren land20.0 t / ha Pasture40.0 t / ha Agriculture66.0 t / ha Plantations 80.5 t / ha Agroforestry83.6 t / ha Forest t / ha 6.00

Carbon sequestration in the wasteland and improvement after afforestation C store (t/ha) C store (No afforestn.) (after 9 yrs. of afforestn.) C store (t/ha) % increase Species: Dalbergia sissoo, Prosopis juliflora, Eucalyptus hybrid Site : Eastern U.P.

Sink Expansion Potential of Sodic Wastelands Sink expansion potential (m t) after 3 years6 years 9 years Prosopis Eucalyptus Dalbergia

Soil Carbon Estimates in Forest Soils Forest/Strata Soil Org. C store (m t) Change Conifers Teak Sal Bamboo Mangrove Hollong Khasi pine Salai Khair Misc ve changes in SC store has been due to – ve change in the area under different species except in conifers, Mangrove and Salai

Source of Soil Carbon estimates The SOC estimates are based on, - published Indian literature mainly on the work of - FRI, Dehra Dun and sister institutions under ICFRE - other research organizations

Proposal There is a need to formulate a strategy for more precise SOC estimates and monitoring thereafter under different forest covers and also under trees outside forest (TOF) etc.

Approach A joint field programme with Forest Survey of India for precise SOC estimates and monitoring, ensuring full correspondence between forest cover and land area.

Strategy - FSI Survey methodology - SOC estimates and monitoring as programmed by FSI for forest cover & TOF - Soil sampling and carbon estimations as per IPCC guidelines